3. Use a "functional core" to centralize mechanicals and divide living and sleeping areas.

4. Place windows strategically to create "virtual space."

5. Vary the size of rooms and ceiling heights to create a sense of movement.

6. Create built-ins with storage.

7. Incorporate sliding doors that can double as moving walls.

8. Use color; define a space with a vividly painted wall.

9. Buy small-scale furniture.

10. Edit. If something big comes in, something else needs to go out.

Some people have closets bigger than the new home that architects Mark Schatz and Anne Eamon have built.

Like a gleaming 560-square-foot jewel box, it's the next phase of an experiment that's occupied their nights and weekends for about 14 years, since they were students at University of Houston. The new home is the third demure structure on their three-lot compound southeast of downtown.

The irony, Eamon said, is that the new house is the smallest but feels the biggest.

"If it's well-designed, a small space can come off seeming twice as big as a poorly laid-out larger space," Schatz said.

North of Loop 610, near Garden Oaks, Rick Russell also is living small - and loving it - in a 540-square-foot cabin designed by architect Donna Kacmar, a UH professor.

Russell, who owns American Medical I.D., lives there three days a week to be close to work. He commutes to Austin most weekends, where he and his wife, Kathleen Smith, are renovating a 2,500-square-foot bungalow that he says now feels like too much house.

Moving from a downtown Houston apartment into the cabin, Russell sacrificed some things others might consider must-haves. There's no stove, for example, because he rarely cooks.

"He just paid attention to how he was living," Kacmar said.

It may sound extreme. But how much house do you really need to live comfortably and well?

"People come in and say, 'We're looking for a small home, but we want lots of big rooms,' " he said. "There's a mentality that they don't need such a big home, but nobody's saying they want a small master bedroom or small closets."

Satisfying a demand for more casual, open living/dining/kitchen spaces, builders can bring down a home's square footage slightly, but many buyers today want two master baths - no shared countertops - plus a second suite for in-laws, Holder said. They also want a study and a media room; and the bedrooms had better be 12-by-12 feet, not the 10-by-10-foot standard of a few years ago.

Brad Kittel, owner the Luling-based company Tiny Texas Houses, thinks most Americans don't use two-thirds of the houses they own until they have guests.

He speaks with rapid-fire zeal about "salvaging America," literally. His easy-to-move, small homes are built of 90 percent reclaimed materials. He's built 50 to date, sized from 120 to 450 square feet, not counting their storage lofts. (His company's name is not exaggerated.)

They look rustic but are built to last, he said. Most of his buyers use them as weekend getaways, although a few occupy their tiny houses full time.

"We'd be selling them like potato chips if we could finance them," Kittel said.

For some, downsizing isn't just about living with a smaller carbon footprint. It's an economic necessity, Kittel said. The nation has 76 million aging baby boomers, he noted, many of whom have spent their lives acquiring stuff and building ever-bigger houses to hold it all. Some are ready to purge and adjusting to smaller-than-anticipated retirement incomes.

Kacmar sees that coming, too.

"You get to a certain point of accumulation and career development, and you're like, 'Is this what I'm working for?' " she said. "How many toilets do you really need to clean? It all adds up to time and money you're spending on stuff you're just taking care of."

Tricks of the trade

On a cold, clear morning last month, dappled light danced through the narrow windows near the ceiling in Schatz and Eamon's new project house. Sitting on the couch, holding their wiggly but content 10-month-old, Wren, Eamon looked out other windows at treetops and sky.

"It's almost like you're not inside; you're in a garden pavilion," she said. "With windows on multiple sides, you never feel contained."

Schatz agreed. "If you place windows strategically where you would otherwise have a sense of closure, like a corner, your eye never settles on the wall; it just moves beyond it," he said. "You're seeing the virtual space of everything around. I'm really big on that."

This is one of many space-expanding - or at least mind-bending - ideas that make the home feel larger than what it is: a 43-by-12-foot rectangle (not counting the exterior overhangs) with an open living/dining/kitchen space, one bedroom and a bath. They'll move in after they finish an addition, planned for early 2012, that will make the house L-shaped and bring it to 900 square feet, with a bedroom for Wren. (She wasn't in the original plans.)

Schatz and Eamon had other priorities when they started their living laboratory in 1997. They bought the land - now a woodsy patch on a dead-end street off Griggs Road - because they didn't have money to build a dream house in Montrose or the Heights.

"We didn't realize what we were doing was so bizarrely different," Schatz said.

They began by building the 700 square-foot home where they've lived since 2000, which will soon become a rental. Two stories, with a footprint of just 360 square feet, it's been featured in Dwell magazine and on HGTV - which helped Schatz and Eamon develop a reputation as small-house specialists.

But their visitors couldn't imagine living in such a small space, so the architects built a second structure in 2005 to show how they might design a 1,200-square-foot house with two bedrooms and two-and-a-half baths. For now, it's home to their M&A Architecture Studio.

Their latest showplace is a small-scale experiment with the kind of materials their clients now want. (Most of M&A's clients are "downsizing" from mansions to homes of about 4,500 square feet.)

"This building is mostly concrete, steel and glass. There's nothing easy or cheap about any of those things," Schatz said. It's also low maintenance and extremely energy efficient, with gourmet appliances, a kitchen wall of glass tile and exotic ipe wood floors.

In small quantities, such high-end finishes are manageable, Schatz said. "You could build a house twice this size for the same price, but you'd have basically a sheetrock box. It's better to pay a little bit more up front. The payback is generally pretty fast, and then it's just better all the way around - better living, better use of materials and natural resources, better use of energy."

So far, Schatz and Eamon have spent about $130 a square foot on the house, doing most of the work themselves. It would cost a client $140-$160 a square foot.

A friend of Schatz's, eyeing the ample closets, described the house as "a thoroughbred horse with really nice saddlebags."

In a small house, everything has to work as efficiently as if it were a Pullman train car, Schatz said. The bath, laundry and big kitchen appliances form a "functional core." The ceiling heights of the rooms vary, to create a sense of movement. Small-scale furniture helps define open zones.

"It's really the idea of total design," Schatz said.

The great outdoors

Architects say to be comfortable, a micro-house must also be set smartly into a landscape with decks, patios or gardens that add liveable space outside.

Eamon and Schatz created a front yard by building a berm that slopes toward their new house from a concrete retaining wall. They envision Wren running up and down the "hills" of drought-tolerant zoysia grass in a few years.

"It's land art, it's landscaping and it's also sort of a recliner," Eamon quipped.

Added Schatz, "There's a wonderful sense of slowness and repose that comes from living small and in a garden space."

Landscaping also figures strongly into Russell's lifestyle.

He put his metal-clad, inner-city cabin at the back of his large lot, so that if or when he sells the property, the next owner can build a larger house in front and use the cabin as a guest house. Or move it away.

At 16-by-34 feet, the cabin is two feet narrower than the Airstream trailer that inspired it. But its sliding doors open onto an 8-foot Ipe-wood deck that overlooks a landscape with multiple "rooms" designed by Rita Hodge.

A hedge of tall black pennisetum purpureum 'Princess Caroline' grass separates the zoysia lawn from a grove of Mexican sycamores set in gravel. Wax myrtle shrubs and crape myrtles mark the yard's western boundary. A large planter near the cabin can be planted to attract butterflies or grow vegetables.

The gleaming Airstream where Russell originally planned to live also is a feature, and potentially a guest bedroom. A city inspector wouldn't let him occupy it full time because it's not in a trailer park, Kacmar said.

She also gave Russell additional outdoor dining space with a built-in counter and stools in the attached, covered carport, where a built-in wood storage shed creates a back wall.

More earthy than M&A's tricked-out new space, Russell's cabin has birch plywood floors stained a deep ebony and waxed. A wall of white oak cladding is whitewashed but rough.

But it's equally energy-efficient, with a similar core separating the living/kitchen area and the bedroom. Since Smith has chemical sensitivities, Kacmar used only low- or no-VOC materials, including blown-in insulation that also makes the house quieter.

Even without a stove, the kitchen meets Russell's needs with a microwave, a refrigerator and a small dishwasher. Kacmar designed built-in shelves and double drawers but avoided hanging kitchen wall cabinets, which would have made the living space feel less integrated - and smaller.

Sliding metal doors secure the cabin and add storm protection. The one element that hasn't been used much is a specially-designed cat door. Russell's cat, apparently, prefers Austin.

Most nights when he's there, Russell watches TV or works on his laptop. When the weather's nice, he sometimes lies on the deck at night, gazing up at the sky while he's talking on the phone.

It sometimes feels like he lives in a vacation home, he said. "There's just less of a to-do-list."